Apparatus for brazing radially extending plates to the interior of a tube



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APPARATUS PLATES I Patented Dec. 30, 1947 APPARATUS FOR BRAZING RADIALLY EX- TENDING PLATES TO THE INTERIOR OF A TUBE William .C. Brown, Watertown, Mass., assignor to Raytheon Manufacturing Company, Newton, Mass., a corporation of Delaware Application February 10, 1944, Serial No. 522,194

6 Claims. (Cl. 113-99) This invention relates to an apparatus for making a multiplex anode structure for a hyperfrequeney oscillator tube of the magnetron type. Tubes f the above type have heretofore been made in which the anode structure comprises a plurality of substantially radially disposed anode arms secured to theinner face of a cylindrical anode block. The space between each pair of anode arms constitutes a cavity resonator. Due to the fact that the frequency of the oscillations produced by such a device depends upon the geometrical configuration of such resonators, and since the efiiciency of such a device depends in large part upon the accurate matching of the cavity resonators, it is particularly important that the anode plates be accurately secured in place. Heretofore difficulties have been encountered in constructing anodes of the above type and the art has resorted to relatively complex and expensive arrangements for insuring proper construction thereof.

An object of this invention is to devise an apparatus for soldering a plurality of anode arms in place in an anode structure of the above described type in a simple and reliable manner.

Another object is to increase the accuracy with which a tube of the above type may be constructed so as to increase the efficiency of operation thereof as a generator of hyper-frequency oscillations. v

The foregoing and other objects of this invention will be best understood from the following description of an exemplification thereof, reference being had to the accompanying drawing wherein:

Fig. 1 is an exploded perspective view partly broken away of the novel apparatus of this invention;

Fig. 2 is a vertical section through the apparatus of Fig. l'showing the wedge members in their assembled position; and

Fig. 3 is a cross-section taken along line 3-3 of Fig. 2.

The multiplex anode structure which is to be constructed in accordance with this invention comprises a cylindrical anode block I made of some suitable highly conductive metal, such as copper, within which are mounted a plurality of anode plates 2 soldered to the inner surface of an annular projection 3 formed upon the inner wall of the block I. The inner edges of the anode plates 2 form a plurality of anode faces adapted to cooperate with a thermionic cathode (not shown) supported centrally of said anode arms 2 constitutes a cavity resonator, the geometrical configuration of which determines the frequency of the oscillations to be generated by the completed device. As already pointed out, it is necessary that these cavity resonators be accurately formed. Also it is necessary that a good electrical contact be created between each of the anode arms 2 and the anode block I. The anode arms 2 are likewise formed of a highly conductive material, such as copper.

In order to construct theanode arrangement as described above, there is provided a jig 4 formed preferably of stainless steel. The jig l is provided with a base portion.5 from which projects a central hollow cylindrical portion 6. The anode block I is adapted to be placed over the cylindrical portion 6, the lower end of said anode block I resting on the base portion 5. The cylindrical portion 6 is preferably of such a height that when theanode block I rests on the base portion 5, the upper edge of the annular projection 3 extends slightly above the upper end of the cylindrical portion 6. The cylindrical portion 6 is also provided with a plurality of radial slots 1 extending from the upper end of said member 6 to substantially the lower end of the annular projection 3. The formation of the slots 1 in the member 6 leaves a plurality of intervening arm members 8. The outside diam After the anode block I is placed on the jig 4,

a plurality of plates forming the anode arms 2 are inserted in the slots "I. These plates 2, when resting upon the bottoms of the slots 1, will thus be supported at the proper level with respect to the annular projection 3. In order to force the anode arms 2 into an intimate contact with the wall of the annular projection 3, and in order to hold the anode plates accurately and firmly in this position, there is provided a lower wedge member ID and an upper wedge member I I. The lower wedge member I0 is provided with a ta pered surface I2, the upper end of which is somewhat smaller than the desired final diametric distance between oppositely disposed anode arms 2, and the lower end of which is slightly greater faces. The space between each pair of anode than this distance. The upper wedge member H has a tapered surface It, the lower end of which is slightly smaller than the above defined final diametric distance between oppositely disposed anode arms 2, and the upper end of which is slightly larger than said distance. The lower wedge member i is provided with a projecting rod I4 which is adapted to fit into a central opening I5 provided in the upper wedge member ll so as to guide said wedge members into alignment.

After the anode plates have been assembled as described above, the wedge members It and II are inserted into the structure, as shown in Fig. 2, and said wedge members are forced toward each other. The tapered surfaces l2 and I3 engage the lower and upper portions respectively of the outer edges of the anode plates 2 and force said anode plates into intimate engagement with the inner wall of the annular projection 3. The wedge members are likewsie preferably formed of stainless steel.

In order to solder the plates 2 in position, a solder ring i6 is laid upon the top surface of the anode plates 2 immediately adjacent the annular projection 3. The solder ring is preferably made of eutectic alloy of copper and silver. The solder ring it is formed so as to possess a certain degree of resilience. The plates 2 are slightly shorter than the annular projection 3 which thus permits the solder ring it to be sprung into position engaging the exposed upper portion of the annular projection 3- After the parts have been assembled as described above, the assembly is placed in a furnace which preferably has a predominantly hydrogen atmosphere. The furnace raises the temperature of the assembly to a point at which the solder i8 melts. It has been found that when such melting occurs the solder runs down along the inner wall of the projection 3 and penetrates into the region between each anode plate 2 and said annular projection. In this way, each of the anode arms 2 is securely soldered in place. It has been found that the soldered joints thus produced are very strong mechanically and have a very high electrical conductivity.

The jig 4 and the wedge members I 0 and ll being made of stainless steel have little if any tendency to stick to the solder. To this extent such stainless steel members may be said to be solder repellent. Moreover it will be noted that the members I0 and H nowhere come into contact with the solder I6 and the only places where the member 4 comes into contact with such solder are at the outer ends of the projection 9. As already pointed out, these are of limited area so that if any tendency to stick exist at these points, the areas are suflicientiy restricted so that the jig 4 may be readily pulled away from the anode structure after the soldering has been completed.

It has been found that anodes may be constructed in accordance with the foregoing with a high degree of accuracy and with great ease and facility.

Of course it is to be understood that this invention is not limited to the particular details as described above, inasmuch as many equivalents will suggest themselves to those skilled in the art. It is accordingly desired that the appended claims be given a broad interpretation commensurate with the scope of the invention within the art.

What is claimed is:

1. Apparatus for use in soldering, comprising: a cylindrical jig member having a longitudinally extending opening, a plurality of substantially radially extending slots passing through the wall of said jig member. said slots extending from one end of said jig member to a distance short of the other end of said jig member, and a pair of wedge members of circular cross-section adapted to be inserted respectively into the upper and lower ends of said longitudinally extending opening, the cross-section of each of said wedge members varying between greater and less than the diameter of said longitudinally extending opening.

2. Apparatus for use in soldering. comprising: a cylindrical jig member having a longitudinally extending opening, a plurality of substantially radially extending slots passing through the wall of said jig member, said slots extending from one end of said jig member to a distance short of the other end of said jig member. a plurality of projections on the outer wall of said Jig member, said projections having their outer ends of limited area lying in a cylindrical surface of diameter substantially greater than the outer diameter of the wall of said jig member, and a pair 01' wedge members of circular cross-section adapted to be inserted respectively into the upper and lower ends of said longitudinally extending opening, the cross-section of each of said wedge members varying between greater and less than the diameter of said longitudinally extending opening.

3. Apparatus for use in soldering, comprising: a cylindrical jig member having a longitudinally extending opening, a base portion, and an upper cylindrical portion of a diameter substantially less than said base portion, a, plurality of substantially radially extending slots passing through the wall of said jig member, said slots extending from one end of said jig member to a distance short of the other end of said jig member, and a pair of wedge members of circular cross-section adapted to be inserted respectively into the upper and lower ends of said longtudinally extending opening, the cross-section of each of said wedge members varying between greater and less than the diameter of said longitudinally extending opening.

4. Apparatus for use in soldering, comprising:

a cylindrical jig member having a longitudinally extending opening, a plurality of substantially radially extending slots passing through the wall of said jig member, said slots extending from one end of said jig member to a distance short of the other end of said jig member, a pair of wedge members of circular cross-section adapted to be inserted respectively into the upper and lower ends of said longitudinally extending opening, the cross-section of each of said wedge members varying between reater and less than the diameter of said longitudinally extending opening, and a rod extension at one end of one of said wedge members, the other of said wedge members having an opening adapted to receive said rod projection to hold said wedge members in alignment.

5. Apparatus for use in soldering, comprising: a cylindrical jig member having a longitudinally extending opening, said jig member being adapted to support a hollow, cylindrical workpiece about the same, a plurality of substantially radially extending slots in the wall of said jig member, said slots extending from one end of said jig member to a distance short of the other end of said jig member and being adapted respectively to receive a plurality of workpieces to be soldered to said first-mentioned workpiece, and a pair of wedge members within said jig member, engaging the opposite ends respectively of said plurality of workpieces, and holding the same in contact a cylindrical jig member having a longitudinally extending opening, said jig member being adapted to support a. heliew cylindrical workpiece about the same, a plurality of substantially radially extending slots in the well of said jig member, said elete extending frem one end of said Jig member t0 8. distance show. of the ether end of said 112' member em? being? adapted respectively te receive piurelifiy e55 Wcrkpiecee te be soldered to seie first-mentieneel werlepiece, e pair of wedge members were seiel m member, engaging the epeo ite cede eeepeetively ef eeiei pluralit 05 were pieces, end midi" the eezee in ccnteei; with we I memieeed workpiece, end weed in said; firsii memiened 6 36188 CITED The following references are of recerd in the tile of this patent:

UNITED STA PATENTS Peechke Sepia. 30,

A 81mm Game in Mefielimw, Scientific ericen, J1me leer, $31-=833, published be Mllmil. emii fie, New YerL-I.

Weielim; Preeeciew, pueiieheri i23 election, New Yerii, wage 

